Turbulence characteristics of the noise producing region of an excited round jet. I - Time-average flow propertiesExperiments were conducted to determine the mean turbulence characteristics of the noise-producing region of a 3 in. cold excited round jet. The jet was excited by plane acoustic waves with a high amplitude of excitation (2 percent of the jet dynamic head), and at a Strouhal number of 0.5. The flow Reynolds number was 280,000. The exit boundary layer was made turbulent by artificially tripping it with sandpaper strips. The data were obtained with single and X-hot-wires and processed in digital form. Mean and higher order statistics were also deduced. The results showed an increase in all three velocity components and stresses. However, most of the increase was noticed from the longitudinal component, while the changes in the radial velocity and the azimuthal component were much smaller. Substantial widening of the jet occurred, accompanied by a shortening of the potential core. Increased rates of production of energy close to the lip-line were a characteristic feature of the mixing region behavior.
Document ID
19850031811
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Baltas, C. (Pennsylvania State Univ. University Park, PA, United States)
Morris, P. J. (Pennsylvania State University University Park, PA, United States)